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- The Parker Solar Probe achieved a record-breaking close approach to the sun, coming within 3.8 million miles.
- The probe, traveling at 430,000 mph, is the fastest human-made object in history.
- Data from this flyby could answer longstanding questions about solar phenomena and their effects on Earth.
LAUREL, Maryland — The Parker Solar Probe zoomed by the sun on Tuesday during a record-breaking flyby, coming within 3.8 million miles of the solar surface during humanity's closest approach to a star.
The mission operations team, located at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, was able to confirm the success of the flyby Friday morning after receiving a signal from the spacecraft just before midnight on Thursday.
The mission team knew it wouldn't receive any communications from the spacecraft during its closest pass of the sun. Now, the team members will await more detailed data from Parker about the spacecraft's status that's expected to return to Earth on Jan. 1.
The uncrewed spacecraft flew at 430,000 miles per hour, which is fast enough to reach Tokyo from Washington, DC, in under a minute, according to NASA. The speedy flyby would make the probe the fastest human-made object in history, the agency shared on Dec. 16 during a NASA Science Live presentation on YouTube.
The mission has been building up to this historic milestone since it launched on Aug. 12, 2018 — an event attended by the probe's namesake, Dr. Eugene Parker, an astrophysicist who pioneered the solar research field of heliophysics.
Parker was the first living person to have a spacecraft named after him. The astrophysicist, whose research revolutionized humanity's understanding of the sun and interplanetary space, died at age 94 in March 2022. But he was still able to witness how the spacecraft could help solve mysteries about the sun more than 65 years after the mission was originally envisioned.
The probe became the first spacecraft to "touch the sun" by successfully flying through the sun's corona, or upper atmosphere, to sample particles and our star's magnetic fields in December 2021.
Over the past six years of the spacecraft's seven-year mission, the Parker Solar Probe has collected data to enlighten scientists about some of the sun's greatest mysteries.
Heliophysicists have long wondered how the solar wind, a constant stream of particles released by the sun, is generated as well as why the sun's corona is so much hotter than its surface.
Scientists also want to understand how coronal mass ejections, or large clouds of ionized gas called plasma and magnetic fields that erupt from the sun's outer atmosphere, are structured.
When these ejections are aimed at Earth, they can cause geomagnetic storms, or major disturbances of the planet's magnetic field, that can affect satellites as well as power and communication infrastructure on Earth.
Now, the time has come for Parker's closest and final flybys, which could complete the answers to these enduring questions and uncover new mysteries by exploring uncharted solar territory.
"Parker Solar Probe is changing the field of heliophysics," said Helene Winters, Parker Solar Probe's project manager from Johns Hopkins University's Applied Physics Laboratory, in a statement. "After years of braving the heat and dust of the inner solar system, taking blasts of solar energy and radiation that no spacecraft has ever seen, Parker Solar Probe continues to thrive."
A blisteringly close flyby of a fiery star
Parker's flyby at around 6:53 a.m. ET on Christmas Eve was planned as the first of the spacecraft's final three closest approaches, with the other two expected to occur on March 22 and June 19.
The spacecraft came so close to our star that if the distance between Earth and the sun were the length of an American football field, the spacecraft would be about 4 yards from the end zone, according to NASA.
At this proximity, the probe would be able to fly through plumes of plasma as well as within a solar eruption if one releases from the sun.
The spacecraft was built to withstand the extremes of the sun and has flown through coronal mass ejections in the past with no impact to the vehicle, said Parker Solar Probe project scientist Nour Rawafi.
The spacecraft is equipped with a carbon foam shield that is 4.5 inches thick and 8 feet wide. On Earth before launch, the shield was tested and able to withstand temperatures near 2,500 degrees Fahrenheit. On Christmas Eve, the shield likely faced temperatures up to 1,800 F, which the telemetry data expected in January will confirm.
Meanwhile, the spacecraft's interior is at a comfortable room temperature so the electronics systems and science instruments can operate as expected. A unique cooling system designed by the Applied Physics Laboratory pumps water through the craft's solar arrays to keep them at a steady temperature of 320 F (160 C), even during close approaches to the sun.
The spacecraft carried out its flyby autonomously because mission control was out of contact with the probe due to its proximity to the sun.
The immense set of data and images gathered during the flyby won't become available to mission control until Parker has moved away from the sun in its orbit, which will occur about three weeks later in mid-January, Rawafi said.
